[Radiance-general] Divide by zero with colorpict

[Jack de Valpine]

I think that this error is resulting from one of the functions in the 
.cal (angmap.cal?) . In this case acos() is probably being fed a value 
outside the bounds -1 to 1, acos() is defined to return an error outside 
these bounds (man acos). An alternative is to use Acos() (see 
rayinit.cal), which I believe forces the boundary condition. It is 
likely that the subsequent divide by zero error is related to the domain 
error with acos(). Of course this is largely a guess based on the error 
output you indicated. If we had the cal to lookout then this might 
provide more information.

-Jack

Kirk Thibault wrote:

> Tarik
>
> One thing I noticed when I did that exercise is that Debevec's world 
> in <angmap.cal> is Y up and Radiance defaults to Z up.
>
> I have no idea if this is a problem from the standpoint of generating 
> the errors below, but it is something that I noticed.
>
> I have gotten multiple "divide by zero" messages from rpict when using 
> IBL as well.  It just keeps on chugging through the calcs though.  Greg?
>
> Here is a link to my Radiance-IBL tests with the Debevec scene and 
> some of my homegrown HDR's (thanks to Debevec's HDR shop and Greg's 
> Photosphere).
>
> http://www.3dfightclubforum.com/phpBB2/viewtopic.php?t=4328
>
> good luck
>
> kirk
>
> On Feb 11, 2005, at 12:38 PM, Tarik Rahman wrote:
>
>> Hi there
>>
>> I'm running the the Debevec tutorial 2002  IBL program that uses 
>> beach.hdr with
>> the spheres on the pedestal and it's rendering with rview but I keep 
>> getting
>> these outputs and it takes ages. I tried changing the .hdr 
>> environment map but
>> the same thing happens. Anyone know what the problem is?
>>
>> ./rview: warning - compute error for colorpict "hdr_probe_image"
>> ./rview: acos: domain error
>> ./rview: warning - compute error for colorpict "hdr_probe_image"
>> ./rview: Division by zero
>>
>> Thanks for any help
>>
>> Tarik
>> -- 
>> Tarik Rahman
>> PhD student, Institute of Perception, Action and Behaviour
>> School of Informatics
>> University of Edinburgh
>>
>>
>> _______________________________________________
>> Radiance-general mailing list
>> Radiance-general at radiance-online.org
>> http://www.radiance-online.org/mailman/listinfo/radiance-general
>
>
>
> _______________________________________________
> Radiance-general mailing list
> Radiance-general at radiance-online.org
> http://www.radiance-online.org/mailman/listinfo/radiance-general
>
>

-- 
#	John E. de Valpine
#	president
#
#	visarc incorporated
#	http://www.visarc.com
#
#	channeling technology for superior design and construction